One popular type might be the ones that focus on their rivalry turning into friendship and then something more. For example, there could be a fanfiction where they start off competing for a spot on the team but gradually realize they have a deeper connection. Another could be set in an AU (alternate universe) where they meet in a completely different context like at a music concert and their relationship blossoms from there.
Some Tumblr blogs also post or recommend Haikyuu fanfictions. You can search for Haikyuu fanfic blogs and then specifically look for Sakusa x Atsumu stories on those blogs. The bloggers often give a little summary or their thoughts on the fics, which can be helpful in deciding if it's something you'd like to read.
One common theme is the 'opposites attract' concept. Given sakusa's quiet and clean - freak nature and atsumu's more energetic and sometimes messy personality, this contrast often forms the basis of their relationship in fanfictions. Another theme is their mutual growth. They help each other become better players and people in many stories.
Angst fiction, well, it's basically about exploring the darker and more troubled aspects of human emotions through fictional stories. For example, a story might be about a young person struggling with self - identity in a cruel society. They face a lot of angst because they don't fit in and are constantly at odds with themselves and the world around them. It can be a very powerful form of storytelling as it delves deep into the human psyche.
Angst fanfiction is a type of fan-written story that focuses on intense emotions, often including feelings of anxiety, stress, or inner turmoil for the characters.
Angst fanfic is all about highlighting the darker, more emotionally intense aspects of the characters' lives. It can involve heartbreak, trauma, or difficult situations that cause them a lot of emotional pain. The aim is to evoke strong feelings in the readers.
They might be really surprised. Some characters could be amused by the creative scenarios fans come up with. For example, Hinata might be excited to see himself in all kinds of wild adventures in the fanfictions.
There are many out there. 'Opposites Attract' is a really nice one. It delves deep into how sakusa's reserved nature and atsumu's more outgoing and flamboyant personality play off each other. The fanfiction does a great job of creating situations where they have to rely on each other, leading to a beautiful relationship development.
The characters might be a bit shy. For instance, if there are fanfictions about Tsukishima and Yamaguchi's friendship, Tsukishima might act like he doesn't care but secretly be a little flattered. Yamaguchi, on the other hand, would probably be more openly happy about it.